Bogor, Indonesia - In the Indonesian city of Bogor, members of a small Islamic sect called the Ahmadiyah tried to ignore the police patrol car parked opposite their mosque as they walked to Friday prayers.
Peering in through the window, I could see them kneeling, facing Mecca, listening to a sermon.
But at any slight noise, several heads turned round nervously.
The Ahmadiyah are afraid and it is obvious why. Hardline Islamic groups want the sect to be banned - they say it deviates from the tenets of Islam, and therefore has no place in Indonesian society.
Over the past few months these hardliners have become increasingly vocal in their demands - holding rallies in central Jakarta and airing their views in the media.
But some have taken it even further. In February, a violent mob bludgeoned three Ahmadis to death. Since then, houses and mosques have been attacked and protesters have vowed to escalate the violence if they do not get their way.
And it is not just hardliners who want the Ahmadiyah disbanded.
In TV talk-shows and internet chat-rooms, it is obvious that an increasing number of Indonesians, while not condoning the violence, would like to see an end to the Ahmadiyah in their country.
One man we spoke to, who lived opposite the Ahmadis' mosque in Bogor, said he thought it would be better if they just went away.
Even the local authorities are making life difficult for them.
In common with some other provinces, officials in West Java - which includes the city of Bogor - have recently issued a new set of decrees restricting the Ahmadiyah's activities.
The Ahmadiyah are not allowed to promote any of their activities, or convert anyone to their faith. They are also being encouraged to attend meetings to re-integrate themselves into mainstream Islam.
So what have the Ahmadiyah done that is causing so much offence?
When I watched their prayers through the window, there did not appear to be any obvious differences between the Ahmadis and the mainstream Sunni Muslims who make up the majority of the Indonesian population.
The men were modestly dressed, and the women - confined to the balcony - wore the hijab. The format seemed virtually identical to Islamic prayers I have seen in other mosques.
Afterwards, when I spoke to Muhammad Harris, the local Ahmadiyah leader, he agreed that his faith was actually very similar to that of his Sunni neighbours.
"The prophet Muhammad is the last prophet - there is no other prophet after him," he said.
"But unlike others Muslims, we believe our founder was a loyal disciple who was chosen to continue the teaching of Islam that came through Muhammad."
Hardline Islamic groups, though, insist the Ahmadiyah faith disputes that Muhammad was the last prophet, and is therefore nothing short of blasphemy - an offence against Islam and a violation of Indonesian law.
And Mohammad Harris is suffering for it.
There used to be a sign outside his mosque saying it belonged to the Ahmadiyah, but that has been taken down now, after officials asked for it to be removed.
People he knows have had to flee their homes after being threatened, and having their mosques and homes attacked.
His own mosque has not been affected, but given the presence of the police patrol outside the building - one plain-clothed officer was even inside, mingling with the congregation - it is obvious that it might be a target.
'Took an oath'
While local authorities have been announcing decrees against the sect, the national government has so far shied away from making any definite pronouncements against the Ahmadiyah.
After all, although Indonesia is the world's most populous Muslim country, it has a secular constitution - including the right to freedom of religious expression.
Nasarudin Umar, the religious ministry's director general for Islamic guidance, said he wanted to explore other measures before banning the Ahmadiyah.
"We're asking Islamic groups, clerics and experts to give comprehensive guidance to both Ahmadiyah members and mainstream Muslims. We believe that the more they understand their religion, the more co-operative they'll be.
"In terms of whether the Ahmadiyah should be banned, we're still studying whether it will be the best."
Other officials, though - including the religious affairs minister Suryadharma Ali - have already decided that the sect should be disbanded.
For human rights groups, this is a very worrying sign. In the past, Indonesia has often been praised for its religious tolerance, allowing many different faiths to live together side by side.
Poengky Indarti, executive director of the rights group Imparsial, said that if the government decided to ban the Ahmadiyah, other minority groups might meet the same fate.
"In the near future I think that it's also dangerous for the Shia groups here in Indonesia, because many Indonesians are majority Sunni - I'm afraid this will become a clash between Islam versus Islam," she said.
But whatever the government tries to do to limit the Ahmadiyah, the one thing it will not be able to do is convert the faithful, Muhammad Harris among them.
"God willing I'll always be an Ahmadiyah," he said. "I took an oath to follow it and I'm going to stick to it."